Interesting patent to let you detach a mobile phone from a pda, reduce the size when you do not need the function of pda.

Description in the patent document,

A mobile handheld electronic device having a given form factor includes a detachable cellular telephone carried within the mobile handheld electronic device, such that when the cellular telephone is positioned within the mobile handheld electronic device the form factor is unaltered.

Just like Windows Mobile smartphone and Palm pda, the pda phone gives you the ability of surfing net, watching tv in a bigger display screen and typing emails with a QWERTY keyboard. A much smaller detachable mobile phone is fixed at the back of the pda phone. You can detach the small mobile phone which comes with basic functions like making calls and smsing. The small mobile phone has its own battery and can be recharged via the pda phone.

Source via mobilearena